Household air conditioning unit



w. L. FLEISHER 2,703,228 HOUSEHOLD AIR CONDITIONING UNIT March 1, 1955 Filed D80. 21, 1953 3 Sheets-Sheet l TTO RN EYS March 1955 w. L. FLEISHER HOUSEHOLD AIR CONDITIONING UNIT 3 Sheets-Sheet 2 Filed Dec. 21, 1953 Nwww xvi/r3 2 R AT 0 R N E Y5 March 1955 w. L. FLEISHER HOUSEHOLD AIR CONDITIONING UNIT Filed Dec. 21, 1953 5 Sheets-Sheet 3 United States Patent HOUSEHOLD AIR CONDITIONING UNIT' Walter L. Fleisher, New City, N. Y., assignor to Air &

Refrigeration Corporation, New York, N. Y., a corporation of New York Application'December 21, 1953, Serial No.-399,373

3 Claims. (Cl. 261-11) tangular screens made of expanded metal with major and minor axes of the openings in adjacent screens in crossed relationship relative to each other. These screens are spaced from each other and the. assembly of screens is mounted in a surrounding frame. The resulting cell is. intended for use in a stationary position in air conditioning apparatus with air flowing through the openings for the purposes of eliminating dust therefrom.

In the instant invention a conditioning cell composed of a. plurality of layers or individual screens of expanded metal is utilized with a household conditioning unit and is located in the path of air flow for the purposes of cleaning the air and also humidifying it. The screens of the cell, however, are assembled in such a way that the cell may be rotated as a unit partially submerged in a reservoir containing water or other desirable liquid. The cell has substantially disc-like or pancake-like shape. The air to be conditioned flows through the unsubmer-ged portion of the rotating cell. In its passage therethrough the dust and other dirt of the in-fiowing air is trapped by the screens of the cell and at the same time the liquid carried out of the reservoir on the surfaces of the cell screens as it has been picked up by submergence in the reservoir is spread in thin films on these surfaces and acts to humidify the air flowing through the cell. The solid portions of the screens between slots or slittings as a re.- sult of expansion of the sheet material from which the screens have been made are twisted out ofthe normal planes of said sheets and act as vanes and miniature buckets which lift fluid out of the reservoiras the cell is rotated. This liquid spreads as a thin film on the vanes in the unsubmerged portion of the rotating celland in its spread washes off trapped dirt picked up by the'v-anes. This dust and dirt as washed off in the unsubmerged-por tions of the cell is carried down; by the return flowof. liquid into the reservoir wherein it settles to the bottom of the reservoir. The dirt collecting at the bottom of the reservoir may be removed readily and periodically through an appropriate drain opening.

The liquid carried out of the reservoir by the vanes of the cell screens flows freely back into the reservoir and carries the dirst washed off the vanes back with it. The outer peripheries of the individual screens forming the cell are free and spaced apart bythe washers on the-main cell shaft and on the through bolts. There are no impediments of consequence therefore. for the return, flow of water and dirt from the cell surfaces to the reservoir. The liquid spreads in thinfilms over the large number of screen surfaces in the unsubmerged portions of the cell and the air flowing through the myriad interstices or screen openings comes in contact with these thin films and is mumidified in such passage. Since the entire. cell rotates each screen has its surfaces thoroughly wetted. by passage through the reservoir and all cell surfaces as they move out of the reservoir are uniformly and thoroughly wetted. This provides maximum cleaning of and maximum moisture or vapor absorption by the air passing through the cell for anygivcndepthof cell. 1

2,703,228 Patented Mar. 1, 1955 Objects of the invention are the provision of a household conditioning unit employing a rotative cell utilizing an assembly of individual screens of expanded material that has the features hereinbefore mentioned.

Other objects and features of the invention are to provide a simply constructed year-round conditioning unit that is efiicient and eifective for the intended purposes.

Further objects and features of the invention are to provide, a compact household conditioning unit whose simplicity of structural detail makes it economical to produce, install and use in average households for effective year-round air conditioning.

Further objects and features of the invention are the provision in such a unit of a novel humidifying and air cleaning cell that is largely self-cleaning during use so that shut-downs for cleaning, repair or replacement of the cells are rarely required.

Other objects and features of the invention will become apparent from the following specification and the accompanying drawings wherein:

Fig. l is a vertical sectional view of a household air conditioning unit embodying the novel cell of this invention, the section being taken along line 11 of Fig. 2

and viewed in the direction of the arrows;

Fig. 2 is an end elevation of the unit of Fig. I viewed from the right end of said figure and being partially broken away to. illustrate internalstructural details;

Fig. 3 is a fragmentary sectional view taken along line 3--3 of Fig. 2 and viewed in the direction of the arrows;

Fig. 4 is a fragmentary plan view, viewed along line 4--'4 of Fig. 2 and in the direction of the arrows;

Fig. 5 is a fragmentary perspective view of a mechanism used in the unit to provide automatic replenishment of hygroscopic material when required;

Fig. 6 is a fragmentary exploded view of a pair of adjacent expanded metal screen elements of the cell as used in this invention, the elements being shown in disassembled relationship;

Fig. 7 is a fragmentary perspective view of a pair of adjacent expanded metal cell screens in superposed relationship and illustrating the crossed relationship of the screen openings therein; and

Fig. 8 is a fragmentary plan view of the cell construc tion as seen along line 8-.8 of Fig. 2 and in the direction of the arrows.

Referring to the drawing, the reference character 10 denotes generally a year-round household air conditioning, unit which includes a novel rot-ative cell of this invention as one of. its components. The unit 10 comprises an overall enclosing housing or casing 12 which has an air inlet opening 13 in one end wall 14 and an air outlet opening 14 at its opposite end wall 15. A vertical partition 16. extending upwardly from the bottom 17 of the housing and in spaced relationship from the housing end wall'1 4-defines a tank or reservoir 18 with said wall. In the embodiment shown this reservoir 18 is adjacent the right end of the housing 12 and lies below the inlet opening 13. The depth of the reservoir 18 is slightly less than half the height of the casing 12 for purposes presently' to be described. The reservoir 18 is supplied with water or other desired liquid by a pipe 19 which is con nected to a source of supply (not shown). The desired level of water or liquid in the reservoir or tank 18 is maintained automatically as by a ball float 20 and a valve 21 which isv controlled thereby. The said valve 2 1 is of conventional construction and is arranged at the outlet of the pipe 19. This outlet overlies the reservoir 18 so that liquid from pipe 19 may flow directly into tank or reservoir 18 whenever the valve 21 is opened by the ball float 20. Any other convenient means for controlling flow of water or other liquid to the reservoir 18 to maintain a desired level therein may be utilized.

An inclined partition 22 is joined at an end 23 to the upper end of the partition 16. The opposite end portion 24 of the partition 22 is secured to a short vertically extending partition portion 25 of a generally horizontally disposed partition 26. The partition 26 extends to the, wall 15 of the housing 12 and is secured thereto as by welding at 27 or in other ways. The parfitiQ lS .16, 2.2 and 26 and the vertical portion 25 of the latter span the space between the front wall 28 and the rear wall 29 of the housing 12. The lower chamber 30 which is defined by the partitions 16, 22, 25 and 26 and the end wall 15 serves as a storage compartment for a suitable compressor 31 (not part of the instant invention) that is used to compress a refrigerant for purposes presently to be described.

A conventional electrically driven blower 32 is mounted internally of the housing 12, for example, on the supports 33 which are located above the partition 26. The inlet 34 of the blower 32 communicates with the chamber or space 35 of the housing 12 above the partitions 26 and 22. The outlet 36 of said blower is positioned to register with the outlet 14 of said casing 12. The blower 32 serves to draw air to be conditioned into the housing 12 via its inlet 13 and through chamber 35 in the direction of the arrows A and thereafter to blow it outwardly from chamber 35 via the outlet opening 14 of the housing 12 and into a duct 37 which is connected to the housing at said opening 14. Air blown into the duct is distributed to the rooms of a house in any desired way.

In its traverse through the chamber 35 of the housing 12 the air passes successively in the direction of the arrows A through a rotating conditioning cell 38, between a set of refrigerating coils 39, through an eliminator 40, and past a reheater 41.

The cell 38 which constitutes a major feature of the present invention is generally pancake-like in shape. By way of example, the cell is approximately 27 inches in diameter and approximately 4 inches thick. Other dimensions may, of course, be utilized. Those given are merely exemplary. The cell 38 comprises a plurality of thin circular screens 42 and 43 which are mounted in alternation on a centrally located shaft 44. The screens 42 and 43 are separated from each other, for example, by interposed spacers or washers 45 mounted on the shaft 44 between adjacent screens.

Each of the screens 42 and 43 is manufactured, for example, in the manner described in the aforesaid Fleisher United States Patent No. 2,636,572. Each screen consists of expanded material such as metal. As described in said patent, the material used to form the screens is preferably flat sheet metal. This sheet metal is provided with a plurality of very fine slots or slits all of which extend parallelly. After slotting or slitting of the individual sheets they are stretched in a direction generally at right angles to the general direction of the slots or slits. This stretching produces uniform openings O in the sheets which appear in the form of a chain of openings which are substantially oval, elliptical or diamond-like in shape and have major and minor axes. The relative dimensions of these openings in their twoaxial directions are dependent upon the amount of stretching to which each slitted or slotted sheet is subjected. During stretching or spreading of the sheets the solid portions P thereof between their slots or slits twist out of the plane of the original sheet so that the stretched sheets have a greater thickness than the original sheets from which they have been prepared.

After the sheets have been expanded as above described they each have a multiplicity of chain-like elliptical or diamond shape openings 0 as seen in Figs. 6 and 7. The sheets after expansion as described are cut into circular shape to provide the respective circular screens 42 and 43. Each of the screens 42 and 43 is provided with a centrally located circular shaft-receiving hole 46 and a pair of diametrically disposed rod or bar accommodating holes 47 or 47a. The shaft-receiving holes 46 are dimensioned to receive center shaft 44. The diametrically disposed holes 47a of the screens 43 are approximately 90 out of phase with the corresponding holes 47 of the screens 42. The holes 47 and 47a of the two screens 42 and 43 are dimensioned to receive tie bars or rods 48 which extend parallelly with the center shaft 44. Because of the fact that the holes 47a in the screens 43 are 90 out of phase with the corresponding holes 47 in the screen 42, it becomes necessary in assembly of the screens 42 and 43 to rotate the screens 43 relative to the screens 42 on the shaft 44 in order that the tie rods 48 may be passed through the holes 47 and 47a of all of the assembled set of screens 42 and 43. In consequence, the major and minor axes of the openings O of the screen 43 are perpendicular, respectively, to the major and minor axes of the openings 0 of the screen 42 (see Fig. 6). In other words, the-openings O in an assembled group of screens 42 and 43 have their major and minor axes is crossed relationship.

Suitable spacers 49 are interposed between adjacent screens 42 and 43 on the tie rods 48. The assembled group of screens 42 and 43 mounted on the shaft 44 and on the tie rods 48 are removably held in assembled relationship thereon by the clamping nuts 50 and 51 which threadedly engage respectively with the shaft 44 and said tie rods 48. In the assembled cell 48 as many as sixteen of the circular screens 42 and 43 arranged preferably in alternation are provided. The number of said screens used is optional and depends upon the depth or thickness of the desired cell 38 and the individual thicknesses of the respective screens 42 and 43 as well as the desired spacing between adjacent of these screens.

The shaft 44 of the cell 38 is supported for rotation in a bearing 51. This bearing is mounted on a frame part 52 secured to the wall 14 of the housing 12 preferably just slightly above the desired level of liquid in the reservoir or tank 18. The level of water or other liquid in the reservoir or tank 18 is maintained by the ball float 20 at such a height that substantially the lower diametrical half of the rotating cell 38 is always submerged in the water during rotation of the cell. The upper diametrical half of the cell 38 which is unsubmerged or above the level of water lies in substantial registry with the inlet opening 13 of the casing 12. In consequence, air drawn into the casing 12 by the action of the blower 32 is compelled to flow through the unsubmerged portion of the cell 38 in the direction of the arrows A which is substantially at right angles to the faces of the screens 42 and 43 of the cell. In its passage through the openings 0 of the screens 42 and 43 the air is cleaned or freed of its dust and dirt content. In addition, the moisture picked up by the cell screens in their rotation through the liquid in the reservoir serves to humidify the air passing through the openings 0 in the unsubmerged portion of the cell.

The dust or dirt removed from the air passing through the cell openings clings to the solid portions P of the individual screens 42 and 43 and is washed ofi and into the reservoir 18 as the cell rotates. In the reservoir these dirt and dust particles drop to its bottom whence they may be removed through a conventional drain outlet 53 whose valve 54 may be periodically opened for drainage purposes.

The shaft 44 of the cell is coupled at 55 to the drive shaft 56 of a motor 57. This motor has a low horsepower rating, being, for example, one whose output is approximately horsepower and whose shaft has a rotational speed of approximately two to three revolutions per minute. The motor 57 may have other power ratings and the rotational speed of its output shaft may be varied as desired. For this purpose a gear reduction device (not shown) may be utilized if needed to provide any desired rotational speed to the cell 38. The motor 57 is supported, for example, on a bracket 58 carried by the frame part 52.

A spray head 59 is supported in the housing 12 above the uppermost unsubmerged peripheral surfaces of the screens 42 and 43 of the cell 38. This spray head 59 is connected by a pipe 60 to a source of water supply (not shown) from which water may be admitted periodically through operation of a valve (not shown) to the spray head 59 for issue therefrom as a spray that will serve to flush accumulated dirt and dust on the surfaces of the cell screens 42 and 43 in the reservoir 18. The provision of the spray head is optional and its use in all event is infrequent.

The set of refrigerating pipes or coils 39 is carried in an appropriate frame 61 which is vertically supported in the housing 12. The lower pipes of the set of coils 39 are submerged in the liquid in the reservoir or tank 18 while the upper pipes of the set 39 lie opposite the unsubmerged portion of the rotating cell 38 on the leaving side of the latter so that the air that has passed through the cell 38 next flows through the spaces between the unsubmerged pipes of the set 39 in its traverse toward the outlet 14 of the casing 12. The set of pipes or coils 39 is connected to the compressor 31 in conventional way as by the pipe 62. The compressor thus serves to deliver refrigerant for expansion in the pipes 39. Such expansion cools the pipes 39 and in consequence cools the air passing through the spaces between unsubmerged ones of said pipes. The submerged pipes of the set 39 cool the Water in the reservoir 18 for purposes presently to be described.

The eliminator 40 is preferably of the type described in Fleisher Patent No. 2,356,757 granted August 29, 1944. Such eliminator, as described in said patent, includes a peripherally arranged open frame 63. This frame carries a palr of superposed layers 64 and 65 of oriented strands of filamentary material, preferably glass. A corrugated wire screen 66 is sandwiched between the layers 64 and 65. The layers 64 and 65 are held within the frame by coarse screens 67 and 68 at their outer faces. The eliminator 40, constructed briefly as just described, is supported within the housing 12, preferably on the partition 22, so that its frame 66 preferably is disposed at an angle with both the horizontal and vertical as seen in Fig. 1. This angular disposition may be that described in the aforesaid Fleisher Patent No. 2,356,757. While the eliminator 40 preferably has the construction. described, other types of eliminators likewise may be utilized. The eliminator 40 is only required in cases where the water in the reservoir 18 has a hygroscopic material such as triethylene glycol mixed with it as will be hereinafter described. When water alone is utilized, the eliminator 40 is usually not required.

The heater 41 is appropriately supported within the housing 12, for example, on the partition 26, and is positioned between the leaving face of the eliminator 40 and the blower 32. This heater is of conventional kind, for example, it may be (a) an electric heater or (b) a plurality of coils in which steam, hot air or hot water from a furnace may flow. The particular construction or type of the heater 41 is not part of the invention. This heater is utilized solely for the purposes of raising the temper ature of the cooled air raising it to any desired degree.

A heating coil 70 is located within the reservoir 18 and is submerged in the liquid therein. This coil 70 may be supplied with steam or other heating fluid from an extraneous source (not shown). An electrically operated valve 71 of conventional kind controls the admission of heating fluid to the coils 70. This valve 71 is connected electrically as by wires 72 and 73 to a hygrostat 74 of conventional kind positioned, for example, in the duct 37. The hygrostat 74 serves to measure the relative humidity of the air blown out into the duct and in conventional way serves to control the opening and closing of valve 71 and consequently the admission of heating fluid to the coil 70. In consequence, the temperature of the liquid in the reservoir 18 may be carefully controlled and thereby the relative humidity of the air emerging from the unit can be controlled.

In wintertime air conditioning it is desirable to utilize a concentrated solution of water and triethylene glycol or other hygroscopic material preferably within the proportional ranges described in Fleisher U. S. Patent No. 2,502,137, granted March 28, 1950. During use of the conditioning unit in which the reservoir 18 contains a water-triethylene glycol or water-hygroscopic material solution rather than water only, the automatic replenishment of the water by operation of the ball float 20 dilutes the solution. In order to prevent the concentration of the solution from falling below the range specified in the aforesaid Fleisher Patent-No. 2,502,137, it is desirable to provide means for automatically replenishing the solution with triethylene glycol or other hygroscopic material. To effect this replenishment automatically, a container 76 (see Figs. 2, 3 and 5) is supported within the housing 12.

This container 76 has a restricted outlet orifice 77 which lies above the surface of the solution in the reservoir 18. The orifice 77 is normally closed by a cover 78 which is suitably pivoted at 79 and actuated by a spring 80 that normally tends to bias the cover 78 into a closing condition relative to the orifice 77. The cover 78 is provided with a projecting flange 81. This flange 81 is positioned to lie in the path of travel of an adjustable pin or screw 82 which is carried by a bracket 83. The bracket 83 is secured to a side surface of a worm gear 84 which meshes with a worm Wheel 85. The worm wheel 85 is fixed to a shaft 86. The shaft 86 has a beveled gear 87 fixed thereto. The beveled gear 87 meshes with a beveled gear 88 fixed to the shaft 44 which latter is driven by the motor 57. In consequence, and by appropriate selection of the gear ratios, respectively, between gears 87 and 88 and between the worm wheel 85 and worm gear 84, the worm wheel 85 may be rotated once approximately for every hundred revolutions of the shaft 44. In other words, the speed ratio between the shaft 44 and the worm wheel 85 is approximately to 1.

The slow rotation of the worm wheel 84 is particularly desirable because once during eachof its revolutions the bolt 82 carried by it through means of the bracket 83 sweeps past the flange 81 of the cover 78 and momentarily swings the cover away from the orifice 77 of the container 76. Whenever this occurs a few drops of triethylene glycol or other hygroscopic material in the container 77 fall into the solution in the reservoir 18. The period during which the cover is maintained in open position relative to the orifice 77 may be adjusted by manipulating the screw 82 and also by controlling the speed ratio between the shaft 44 and the worm gear 84. Since the amount of triethylene glycol or other hygroscopic material that must be supplied from the tank 76 for replenishment purposes is very small, the frequency of opening of the cover 78 is very low. This low frequency is controlled by the speed ratio between shaft 44 and whleel 85, as mentioned above, and is of the order of 100 to For convenience, the upper end'of the container 76 is accessible through the top of the housing 12 and is provided with a removable cover 89 for refilling purposes.

Any other convenient way of maintaining the desired concentration of the solution in the reservoir 18 may be employed. The use of the replenishment mechanism just described depends upon whether or not the unit is to be utilized both for winter and summer air conditioning purposes. If only summer use is contemplated, the replenishment mechanism just described may be omitted as no triethylene glycol is utilized during the summertime.

Assuming that the unit is being utilized during wintertime air conditioning, all the components hereinbefore described are present in the unit and it operates as follows:

Reservoir 18 is filled with a solution containing water and triethylene glycol to the level permitted by the float 20. The solution preferably is one as mentioned in the said Fleisher Patent No. 2,502,137 wherein the concentration of triethylene glycol is within the range of 82% to 92% by weight of said solution. The container 76 is filled with concentrated triethylene glycol solution. The motor 57 is started and the blower 32 is also started.

The motor 57 causes the cell 38 to rotate slowly through the solution in the reservoir 18. The blower 32 draws outside air in through the opening 13 of the housing 12 and through the unsubmerged portion of the rotating cell 38. The direction of air flow through the cell 38 is indicated by the arrow A in Fig. 1. This direction, it is to be noted, is substantially perpendicular to the faces of the individual screens 42 and 43 of the cell 38. The air flows through the openings 0 in the unsubmerged portions of the screens 42 and 43. In this passage through the openings it comes in contact with the solution-wetted surfaces of the screens 42 and 43 adjacent the openings. Any dirt contained in the air is trapped by the screens 42 and 43. At the same time because the screens 42 and 43 are wet, the air passing through them is humidified by its contact with the solid wetted portions P of the screens. On leaving the last of the screens of the cell 38 the air is next drawn through the spaces between the refrigerating coils 39. Refrigerant from compressor 31 may or may not be supplied to coils 39 for refrigerating expansion, depending upon the temperature of the air being drawn into the unit 10. If the compressor 31 is off, no refrigerating action occurs as the air passes in the spaces between coils 39. If the compressor 31 is on, the expansion of refrigerant in pipes 39 cools air passing in surface contact with unsubmerged ones of these pipes 39. The submerged pipes 39 cool the liquid in reservoir 18.

The air after transit beyond pipes 39 then passes through the eliminator 40 which serves primarily to eliminate any entrained droplets of liquid that may be present in the air. The droplets of liquid trapped by the eliminator 40 travel downwardly in the latter, flow down the inclined partition 22 and back into the reservoir 18. The air leaving the eliminator 40 flowspast the heater 41 which elevates its temperature to that ultimately desired. After passing the heater 41 the air duct 37 for delivery from the latter to desired places in the house.

The hygrostat 74 in the duct 37 measures the relative humidity of the air entering said duct. By this measuring action it serves to operate the electrically controlled valve 71 of the heating coil 70 in the reservoir 18 and to elevate the temperature of the solution in the latter to a temperature sufiicient to effect overall humidification of the air passing through the unit 10 to a point sufiicient to satisfy the condition for which the hygrostat 74 has been set.

Because of the rotation of the cell 38 in the reservoir 18 the dirt trapped in its unsubmerged portions above the level of the reservoir is flushed into the reservoir. The flushing action is enhanced by the twisted portions P of the individual screens 42 and 43 around their various openings 0. These twisted portions P act as miniature paddles to agitate the solution. This agitation washes clinging dirt from the screens 42 and 43. At the same time the twisted portions of the screens act as miniature buckets which carry enough solution out of the reservoir 18 as the succeeding submerged portions of the cell rise therefrom to insure the fact that the unsubmerged portion of the cell 38 is moist throughout during the contact therewith of the air drawn therethrough.

It is to be noted that the screens 42 and 43 are supported solely by the center shaft 44 and the two tie bolts or rods 48, and are individually spaced from each other by the washers 45 and 49. No binding or outer peripheral frame is provided at the peripheral edges of the screens. There are no obstructions at the outer ends of the spaces between screens. In consequence, during rotation of the cell, each individual screen cuts through the reservoir water independently. There is also no possibility of an accumulation of clogging dirt at the periphcries of the screens as would be the case if a peripheral frame were utilized. The dirt flushed off the screens 42 and 43 settles at the bottom of the reservoir 18 and is ieargiy removed through the valve-controlled drain out Moreover, because the individual screens 42 and 43 are spaced from each other by the use of the spacers on the shaft 44 and on the tie rods or bolts 48, the water or other liquid in reservoir 18 penetrates and circulates fully, simultaneously and in identical manner to and about each of the screens 42 and 43 during their rotation. In consequence, each of the screens is equally wetted so that the air passing through the unsubmerged portions of the rotating screens is affected by successive passages through a plurality of equally wetted screens. The simultaneous and equal wetting of the plurality of screens provides greatly enhanced efficiency of operation in contrast with systems wherein each succeeding screen or conditioning cell in a series of screens or cells is successively wetted by water drippings from a preceding screen. The frameless support of the screens 42 and 43 in spaced relationship as described herein always insures equal wetting of all screens irrespective of the number of the screens used to make a revolving cell 13.

During rotation of the cell 38 its shaft 44 drives the shaft 86 through the bevel gears 88 and 87. In consequence, the worm wheel 85 rotates the worm gear 84 and causes periodic opening of the cover 78 once approximately for every 100 revolutions of the shaft 44. Each time the cover 78 is opened a few drops of triethylene glycol or other hygroscopic material in container 76 fall into the reservoir 18 and replenish or compensate for triethylene glycol that may have been evaporated. The small amount of triethylene glycol added periodically by operation of the cover 78 is sufiicient to maintain the desired concentration of triethylene glycol in the solution of the reservoir 18. Water lost from the reservoir 18 by evaporation or otherwise is automatically replenished by operation of the float 20 which opens and closes the valve 21 in the pipeline 19.

When the unit is used only during the summertime the eliminator 40 may be removed and the heater 41 may be maintained in an inactive condition. Similarly during the summertime the container 76 may be kept empty.

Since the cell 38 is partially submerged in the water of the reservoir 18 and since some of the pipes of the refrigerant-carrying set 39 are also partially submerged in the solution in the reservoir 18, the submerged pipes 39 act as an inter-changer and serve to cool the solution in the reservoir. The cool solution picked up by the rotating cell 38 and carried around into its unsubmerged portion has a cooling effect upon the air passing through the cell. This reduces the necessary number of unsubmerged cooling pipes 39 and the necessary area and period of surface contact of air with such pipes for the ultimately desired cooling effect upon the air that it is intended to condition by transit through the unit.

While specific embodiments of the invention have been disclosed, variations in structural detail within the scope of the appended claims are possible and are contemplated, there is no intention therefore of limitation to the exact details shown and described.

What is claimed is:

1. An air conditioning unit comprising a reservoir for liquid, means for maintaining liquid at a predetermined level in said reservoir, a cell partially submerged in the liquid in said reservoir, means for rotating said cell, storage means for hygroscopic material, control means for delivering hygroscopic material from said storage means to the liquid in said reservoir to maintain a predetermined concentration of hygroscopic material in said liquid, means for operating said control means by the rotation of said cell, refrigerating means in said unit also partially submerged in the liquid in said reservoir, eliminator means in said unit and means for drawing air through said unit successively through unsubmerged portions of the rotating cell, an unsubmerged portion of said refrigerating means, and said eliminator means and for thereafter blowing it outwardly of said unit.

2. The air conditioning unit of claim 1 including heating means past which the air is also drawn in its passage through said unit and subsequent to its passage through the unsubmerged portion of said cell.

3. The air conditioning unit of claim 1 including a heating means submerged in the liquid of said reservoir for regulating the temperature of the said water and means responsive to the relative humidity of the air blown outwardly of said unit to control the heating action of said submerged heating means on said liquid.

References Cited in the file of this patent UNITED STATES PATENTS 1,345,131 Cleworth June 29, 1920 2,054,039 Persons Sept. 8, 1936 2,143,628 Lea Jan. 10, 1939 2,493,726 ODay Jan. 3, 1950 2,636,572 Fleisher Apr. 28, 1953 

